Understanding the Basic Ingredients Helps Avoid Floor Care Problems

by Roger McFadden

INTRODUCTION

Chemists and floor care professionals often speak different languages. The chemist talks about polymerization, melting points and monomers. And the floor care professional talks about durability, wet-look gloss and burnish response.

As a chemist specializing in floor finish development I have learned the importance of communicating and listening to floor care professionals. Professionals are the ones who use the floor finishes. It is their needs that we chemists must satisfy.

Floor care professionals are very cooperative in teaching us chemists about their floor finish procedures, application methods, and equipment. But most floor care experts that I know are as interested in learning more about the floor finishes they use as I am in learning about their techniques and procedures.

Two questions floor care professionals often ask are, 1) what is in a floor finish? and 2) why is it in there?. Let's look at the answers to these questions to better understand how to prevent and solve expensive floor care problems.

 WHAT ARE FLOOR FINISHES?

A floor finish is a liquid which is applied to a resilient tile floor and dries to a hard, durable and smooth film. This film is about the thickness of waxed paper and is expected to protect and extend the life of the floor while providing an attractive appearance and slip resistant surface.

WHAT’S IN A FLOOR FINISH

High quality floor finishes may contain as many as twenty-five ingredients. Some of these ingredients evaporate while others remain on the floor after drying. The ingredients that evaporate are called, "volatile" components and the ingredients that stay on the floor are called, "non-volatile" components. The volatile ingredients assist in the film formation, drying and curing of the finish and then evaporate. The non-volatile ingredients are the solid materials which stay on the floor and make up the floor finish film.

The ingredients used to make floor finishes combine to produce a balanced blend of physical and performance characteristics. Some of these characteristics include: hardness, gloss, clarity, scuff

resistance, slip resistance, water and detergent resistance, buffability, removability, recoatability, and toughness.

There are five basic categories of floor finish ingredients, (1) polymer emulsions, (2) film formers, (3) modifiers, (4) preservatives and (5) water.

 POLYMER EMULSIONS

A polymer is a giant molecule made from a large number of similar small molecules, called monomers, which are joined together chemically. The chemical process of making a polymer is called polymerization. When a polymer is made from two or more monomers, it is called a copolymer. Many polymers are named for the monomer from which they are made. For example, the polymer polyethylene is named for its monomer ethylene.

Chemists suspend the giant floor finish polymer in water, and they become polymer emulsions. Most floor finish manufacturers treat the monomers and processes used to make their polymer emulsions as a trade secret. However it is generally known that most floor finish polymer emulsions are made from acrylic or styrene type monomers.

The polymer emulsions are the workhorse of a floor finish. They are the backbone upon which all of the other ingredients are connected. There are virtually thousands of potential combinations of polymers which can be used to make floor finishes. The choice of the polymers used in floor finishes influences nearly every performance characteristic, including: durability, gloss, slip resistance, leveling, clarity, water and detergent resistance, recoatability, mark resistance, removability and powder resistance.

FILM FORMERS

Polymer emulsions without film formers would produce dry, loose crystals on the floor surface. Improper film formation can produce a variety of floor care problems including: poor adhesion and powdering, poor gloss, streaking, cratering, fisheyes, blushing, orange peeling and poor leveling. Some of the ingredients that contribute to proper film formation are coalescing agents, plasticizers, wetting and leveling agents and antifoamers.

Coalescing Agents

Coalescing agents such as glycol ethers, glycol ether esters and ester-alcohols allow the polymer molecules suspended in the emulsion to coalesce (come together) into a continuous film without flaws or imperfections on the floor (See Figure 3). Coalescing agents stay behind for a short time after the water has evaporated to soften and bring the polymer molecules together into a continuous and tough film.

A precise amount of coalescing agent is needed for proper film formation. For this reason it is important for floor care professionals to minimize evaporation by keeping floor finish containers and mop buckets, covered or closed when not in use. Floor care problems associated with a loss of these coalescing agents include: poor adhesion, low gloss and poor durability.

Plasticizers

Floor finish polymers would crack and break without plasticizers to make them flexible and impact resistant. Chemists are careful to design floor finishes with accurate amounts of plasticizer. "Over plasticized" floor finishes can produce tackiness, poor soil resistance and plasticizer migration. "Under plasticized" floor finishes can create powdering, low gloss, slippery floors and recoatability problems.

Leveling and wetting agents

The polymers in floor finishes are bulky and have high surface tension which prevent proper flowing and leveling of the finish. Leveling and wetting agents lower the surface tension of the finish allowing it to spread and flow over the floor surface uniformly and evenly. Tiny amounts of these surface active agents provide big benefits by preventing the finish from pulling apart and puddling during the drying process.

Antifoaming Agents

Water based floor finishes contain small amounts of surfactants and emulsifiers which can produce bubbles and foam in the dried film. These surface flaws, sometimes described as craters and fisheyes, destroy the smooth and reflective appearance of the dried film. Antifoaming agents are added to floor finishes to rapidly break these bubbles and stop them from producing ugly imperfections.

MODIFIERS

The polymer emulsions selected for floor finishes meet a broad range of performance requirements. But chemists have found non-volatile ingredients which can be added to the polymer emulsion to modify and improve the performance of the floor finish. For instance, gloss, clarity, hardness, buffability, scuff and scratch resistance, slip resistance and durability can all be improved when modifiers like resins, wax emulsions, urethanes, ultraviolet absorbers and metal crosslinkers are added.

Alkali Soluble Resins

There are three primary alkali soluble resins which are used in floor finishes. They include, (1) rosin, (2) acrylic and (3) styrene-maleic anhydride resins. These resins are added to floor finishes primarily to improve leveling, clarity and gloss. However, they also affect many other properties including removability, detergent resistance, color, recoatability and water resistance.

Wax Emulsions

The wax emulsions added to floor finishes are synthetic polyethylene or polypropylene waxes which have replaced natural waxes because of their improved consistency in color, performance and availability. Their major contribution to the floor finish is improved slip resistance, durability, toughness and high speed buffability.

Waterborne Urethanes

These are used in floor finishes where chemical and water resistance, impact resistance, and flexibility are required. When combined with polymer emulsions, they also provide improved adhesion to old and worn floor surfaces. Three objections often mentioned when high levels of waterborne urethanes are used in floor finishes are their cost, tendency to discolor and removability.

 Ultraviolet Stabilizers

The effect of ultraviolet radiation on synthetic polymers is similar to its effect on the human skin. The ultraviolet radiation can cause yellowing and drying out of the finish. Floor finishes contain tiny amounts of stabilizers to prevent yellowing and discolorations caused by ultraviolet radiation.

Crosslinkers

Crosslinkers connect the different polymer chains in the floor finish emulsion. Their primary purpose is to provide both durability and removability of the floor finish film. Zinc compounds commonly are used to crosslink acrylic polymer floor finishes.

 PRESERVATIVES

Some of the ingredients in floor finishes are sensitive to attack by microorganisms. These attacks can destroy the floor finish and cause discolorations, destruction of the floor finish emulsion and unpleasant odors. Formaldehyde has been the primary antimicrobial agent used in floor finishes for over 20 years. But most modern floor finishes now contain new replacements, due to health issues raised by formaldehyde.

Antimicrobial agents are added to protect the finish by preventing the growth of microorganisms during manufacturer and storage. However, the amount of antimicrobial agent in a floor finish is usually not sufficient to protect against cross contamination during use. This is why floor care professionals should keep their finishing equipment clean, and insist on never pouring used finish into new finish.

Another type of preservative added to floor finishes is the antifreeze agent, which provides freeze-thaw stability.

WATER

Floor finishes are made with deionized water to provide a stable and friendly environment for all the floor finish ingredients. The use of deionized water assures that colorful impurities found in some water systems do not dry into the floor finish film causing slight discolorations or reductions in gloss or clarity.

CHEMISTRY AND CARE COMBINE

The ingredients described here are a good cross-section of what many floor finishes contain, but they are not the only ones. You can get more information about the finishes you use by contacting your sanitary supply distributor or the finish manufacturer.

Teamwork between chemists and floor care professionals has produced modern finishes far superior to those of the past. But it takes more than a superior finish to defend against the abrasive soils tracked into buildings. It also takes a well-planned and well-executed floor care program that is designed to do the job right. Knowing the ingredients in a finish and why they are used can help cleaning managers select the proper finish and prevent expensive floor care problems.